The audible gasps that briefly echoed around the Emirates Stadium when Adlene Guedioura spectacularly clinched Watford's place in the FA Cup semi-final were soon replaced by increasingly familiar and angry boos.

The audible gasps that briefly echoed around the Emirates Stadium when Adlene Guedioura spectacularly clinched Watford's place in the FA Cup semi-final were soon replaced by increasingly familiar and angry boos.

The noise of fan discontent is threatening to become not just the soundtrack to Arsenal's season but also what would be a desperately sad ending to Arsene Wenger's tenure at the club.

There is no imminent threat to his position but the mounting frustration, tension and division among the fanbase has become stark.

There were even scuffles outside the Emirates yesterday between Arsenal supporters and, although the mood is sufficiently transient to again swing quickly, it will now take a quite dramatic and unlikely turnaround to salvage a season that once promised so much.

The dream of becoming the first club for 130 years to win three consecutive FA Cups has ended and, with elimination from the Champions League at Barcelona on Wednesday looking like a formality, it is the Premier League that now represents the only serious chance for silverware.

Ominously

With only nine matches to go, the respective gaps to Leicester City and Tottenham have grown ominously over the past month to eight and six points.

Yet the deepest frustration lies not just in the terrible timing of a run of four wins in 14 matches but that familiar problems are again being repeated.

This Arsenal squad have simply lacked the depth and resistance from injury to cope with a sequence of seven matches over the past 23 days and defensive weaknesses have been evident at the critical moments.

The most glaring mistake here was not just the obvious errors that led to Watford taking the lead through Odion Ighalo but how the team then responded by pushing forward and leaving open the spaces from which Guedioura sealed their fate with a finish of astonishing power.

It was Watford's first FA Cup win over Arsenal since 1987 and ensured their first semi-final in the competition since 2007.

Quique Sanchez Flores even described it as the greatest win of his distinguished managerial career and, with the fans celebrating ecstatically inside the Emirates, revealed that there were similarly joyous scenes in the away dressing-room.

Although Wenger left first-choice full-backs Nacho Monreal and Hector Bellerin on the bench, he did otherwise select a full-strength team.

Arsenal did also begin with the greater energy, with Alexis Sanchez quickly dissecting Watford's defence, only for Olivier Giroud to have drifted narrowly offside before having his finish past Costel Pantilimon ruled out.

Two excellent further Arsenal chances were then wasted by Mohamed Elneny. The first was miscued wildly and then, after some wizardry by Mesut Ozil and a precise Joel Campbell lay-off, an attempted side-footed finish also sailed high and wide.

For all their possession, Arsenal were alarmingly open defensively. Starting Calum Chambers next to Per Mertesacker ensured a fairly chronic lack of pace whenever Watford counter-attacked down the left, with Ighalo twice getting into excellent positions before wasting the moment with a poor pass. Gabriel was also erratic and Arsenal were fortunate to keep 11 men on the pitch following a two-footed tackle on Troy Deeney that was not even judged a foul.

Watford had not scored in three games but carried a persistent threat and did then punish more lax defending. Deeney climbed above Chambers and Mertesacker to guide a throw-in towards Ighalo who, with his back to goal, was allowed to turn by Gabriel and guide his finish past David Ospina.

Arsenal did almost strike back immediately when Campbell crossed for Giroud but an attempted finish with his outstretched toe was foiled by an excellent reaction save by Pantilimon.

Premature

There was still half an hour remaining but Arsenal then showed that they have learnt little from past mistakes by pushing forward with premature urgency for an equaliser.

Watford were content to wait on the counter-attack, with Deeney then holding up the ball long enough to roll a pass into the direction of Guedioura. He did not break stride before smashing a finish inside Ospina's near-post.

Wenger immediately introduced Danny Welbeck, Theo Walcott and Alex Iwobi and there was suddenly more pace and urgency in his team.

With full-time looming, Sanchez fed Welbeck who then collected a delightful Ozil back-heel before side-footing his finish past Pantilimon.

Too early, I think, to call for Arsene Wenger's head now. Eight points behind leaders Leicester City with nine games to go, it is not inconceivable that Arsenal could yet win the league this season.

Doubtful, yes. I cannot deny that, especially after another limp display full of familiar faults. But that, in itself, is not the issue. As someone sarcastically tweeted, "Typical Wenger, not winning the FA Cup three years in a row".

Many rival fans, in fact, think it faintly ridiculous that a Champions League regular vying for the title from a beautiful stadium should even come close to supporter revolt.

"You wanna see what it's like at our place. Fancy swapping places?"

And you can definitely see their point. Then again, I can also understand those mutinous Gooners paying through the nose for tickets.

It has been going on for too long, this weakness of spirit that sees the side falter whenever push comes to shove.

Forget about the cup. Two wins from the last nine Premier League games is no kind of reaction to this crucial period - or the form to back up Wenger's claims, repeated yesterday, about "great spirit" and "a strong attitude" within the camp.

The buck can only stop with the manager. It is Wenger who decides what kind of character he wants in the dressing-room, Wenger who works with those players on the training ground. But whatever he does in the week, the team continues to lose its shape in the heat of battle.

Despite all this, the old banner still hangs at the Emirates: "In Arsene We Trust". But if Arsenal's season now dribbles to a sad close, that trust can surely be extended no further.